<!doctype html>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script>
promise_test(async t => {
  let start_length = navigation.entries().length;
  let start_index = navigation.currentEntry.index;

  // Wait for after the load event so that the navigation doesn't get converted
  // into a replace navigation.
  await new Promise(resolve => window.onload = () => t.step_timeout(resolve, 0));
  await navigation.navigate("#foo").committed;
  assert_equals(navigation.entries().length, start_length + 1);

  let oncurrententrychange_back_called = false;
  let back_committed = false;
  navigation.oncurrententrychange = t.step_func(e => {
    oncurrententrychange_back_called = true;
    assert_equals(e.from, navigation.entries()[start_index + 1]);
    assert_equals(e.navigationType, "traverse");
    assert_equals(navigation.currentEntry.index, start_index);
    assert_false(back_committed);
  });
  let back_result = navigation.back();
  assert_false(oncurrententrychange_back_called);
  await back_result.committed.then(() => back_committed = true);
  assert_true(oncurrententrychange_back_called);

  let oncurrententrychange_forward_called = false;
  let forward_committed = false;
  navigation.oncurrententrychange = t.step_func(e => {
    oncurrententrychange_forward_called = true;
    assert_equals(e.from, navigation.entries()[start_index]);
    assert_equals(e.navigationType, "traverse");
    assert_equals(navigation.currentEntry.index, start_index + 1);
    assert_false(forward_committed);
  });
  let forward_result = navigation.forward();
  assert_false(oncurrententrychange_forward_called);
  await forward_result.committed.then(() => forward_committed = true);
  assert_true(oncurrententrychange_forward_called);
}, "currententrychange fires for same-document navigation.back() and navigation.forward()");
</script>
